Urinary tract health is an increasingly important health issue, e.g., based on an aging population. Treatment of urinary tract conditions is an area of much investigation. Many methods and devices have been proposed to deliver therapeutic materials such as therapeutic fluid to the urinary tract, e.g., kidneys, ureters, and lower urinary tract (urethra, prostate, bladder, bladder neck).
Much effort has been focused on treating prostate tissue. Prostate disease is a significant health risk for males. Diseases of the prostate include prostatitis, benign prostatic hyperplasia (BPH, also known as benign prostatic hypertrophy), prostatic intraepithelial neoplasia (PIN), and prostatic carcinoma.
In addition to prostate conditions, other tissue of the urinary tract can be affected by medical conditions that can be treated by delivery of various therapeutic materials in the form of fluids. Tissues of the bladder (which includes the bladder neck), ureter, kidneys, urethra, as well as the prostate, can be treated by delivery of drugs or other therapeutic agents.
Various treatments of the bladder that are currently used or proposed, such as transurethral administration of an active pharmaceutical agent, involve placement of a therapeutic fluid into the bladder using a single needle located at the distal end of a rigid shaft inserted into the bladder through the urethra. These methods can involve various difficulties or undesired effects and can be difficult to perform.
Needleless devices and methods for treating tissue of the urinary tract are discussed in Applicants' copending application Ser. No. 12/087,231, filed Jun. 27, 2008, by Copa et al., titled DEVICES, SYSTEMS, AND RELATED METHODS FOR DELIVERY OF FLUID TO TISSUE, and U.S. Publication No. 2006-0129125, the entireties of these disclosures being incorporated by reference. A wide variety of medical treatments are at least partially performed through the delivery and introduction of therapeutic compositions to a treatment location by way of needless injection. For example, diseases of the prostate such as prostatitis, benign prostatic hyperplasia, and prostatic carcinoma, are treated by injection. Surgical methods used to relieve the symptoms of BPH include methods of promoting necrosis of tissue that blocks the urethra by chemical ablation (chemoablation). In one chemical ablation technique, absolute ethanol is injected transurethrally into the prostate tissue. This technique is known as transurethral ethanol ablation of the prostate (TEAP). The injected ethanol causes cells of the prostate to burst, killing the cells. The prostate shrinks as the necrosed cells are absorbed.
One way in which therapeutic fluids can be delivered internally is through the use a tube-like device configured to provide a jet-injection of the therapeutic fluid at a desired treatment site. Generally, a needleless injector is to deliver the therapeutic fluid from an external reservoir located at a proximal end of the tube-like device with such administration occurring at a distal end of the tube-like device. Due to the relatively long travel length of the therapeutic fluid through the tube-like device, the remote injector must generally be capable of pressurizing the therapeutic fluid to pressures exceeding about 2,000 psi. To accommodate these pressures, the tube-like devices have been fabricated of alloys such as NiTi or stainless steel or with metal-reinforced polymers such as the braided tubes typically found in catheters. While the use of alloys and metal reinforced polymers satisfy the operational requirements related to burst pressure and distention strength, they are generally of limited flexibility making them difficult to navigate within the tortuous paths often found in the human body such as, for example, the urogenital tract.
According to certain methods of injecting the prostate, a transuretheral flexible endoscopic probe is directed to the area of interest. Because a flexible endoscope is rotated inside bends, the injection tube will tend to uncontrollably rotate inside the channel of the endoscope because it does not have equal bending stiffness in all degrees of movement. Moreover, the articulating section of the flexible endoscope can typically only bend on one direction making compound bends impossible. This is a problem in the anatomy around the prostate. Therefore there is a need to fix the injection tube in a preselected orientation so as to enable an injection in the desired direction.
Furthermore, treatment is more efficiently performed if the injection orifice is proximate the target tissue. As the injection catheter is directed through the channel to the target tissue, whether within the endoscope or independently, it is unacceptable to simply rely on luck for proper placement. Thus there is a further need to direct the injection orifice proximate the target tissue with the minimum of moving parts and complexity due to the space constraints.
Different practical challenges exist for performing injections of other types of tissue. Some tissues, such as bladder tissues, are thin in their depth dimension (i.e., shallow), making injection a challenge. For these tissues, there is ongoing need to improve injections, such as by increasing uniform distribution of agents within the thin tissue, over a desired area of the tissue.
For any injection or injected tissue, therapeutic agents should be delivered with minimized discomfort and procedure time, and with the best possible degree of accuracy of delivery location and delivery volume, and with uniform and accurate distribution of a fluid throughout injected tissue. As such, there exists continuing need to provide improved devices for delivering therapeutic fluids to different tissues including but not limited to locations of the urinary tract including the bladder, bladder neck, prostate, urethra, kidneys, ureters, etc.